L 9 1 0—1 1 . ] Isopiestic Expansibility of Water. 465 
Before the experiment the following weights were taken : — 
Wt. of empty dilatometer .... =10*018 g. . . (1) 
Wt. of mercury entirely filling bulb AB . = 6*856 g. . . (2) 
Wt. of dilatometer with mercury A to F . =32*612 g. . . (3) 
Wt. of dilatometer with liquid A to K, and 
mercury K to F . . . = 28*994 g. . . (4) 
Wt. of mercury removed from EF . . = 2*785 g. . . (5) 
Calculations : — 
Neglecting meanwhile all corrections, — — ^ gives original volume ; 
iZ'Ou 
.*. original volume is equal to *288 c.c. . . . (a) 
(5) 
Again . ^ ^ gives change of volume ; 
.*. change of volume is equal to *205 c.c. . . . (b) 
Finally, (4) — (5) gives weight of dilatometer with contents before 
experiment. This weight is equal to 26*209 g. . . . -(c) 
While the dilatometer was in the compression-cylinder the observations 
given in the following Table were made : — 
Observed Pressure 
in kgs. /cm. 2 = 
1000. 
700. 
400. 
Observed Temperature 
°C. when contact is — 
Made. 
Broken. 
Made. 
Broken. 
Made. 
Broken. 
— 
— 
— 
— 
— 
— 
420 
410 
375 
368 
338 
325 
413 
410 
373 
365 
328 
325 
413 
410 
373 
360 
328 
323 
Calculated Average ) 
Temperature in °C. f 
413 
369 
328 
After the experiment the following weights were taken : — 
Wt. of dilatometer and contents after experiment 
= 26*198 g. . 
■ (6) 
Wt. of mercury in bulb K to B . 
= 2*922 g. . 
(7) 
Wt. of empty dilatometer ..... 
= 9*995 g. . 
. (8) 
From these and the previous weights we calculate again the original 
volume from ^ ■ - - ^P ; 
13*56 
.*. original volume is equal to *290 c.c. . . . (d) 
VOL. XXXI. 
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